The practice of dispensing heavy and particulate materials through traditional aerosol spray can valve assemblies in the aerosol industry has presented problems in which the heavy and particulate materials to be dispersed clog up the valve assemblies. These heavy and particulate materials may include exterior stucco, heavy sand finishes, drywall and acoustic ceiling patching materials, fire suppressant materials, adhesive and bonding materials, and even culinary sauces.
A traditional aerosol spray can may be filled with these heavy and particulate materials for spraying. However, because of the placement of the valve assembly in traditional aerosol spray cans, these heavy and particulate materials will clog up the valve assemblies and render the aerosol spray cans inoperative. Constant operation of these aerosol spray cans in spraying heavy and particulate materials is not possible due to the inconsistent ability of these traditional valve assemblies to dispense these materials without clogging.
U.S. Pat. No. 5,715,975, issued to Stem et al., discloses an aerosol spray texturing device that is comprised of a container, a nozzle, a valve assembly, and an outlet. The valve assembly in the ""975 patent is located in the upper section of the container near the nozzle. Although the nozzle tube of the device in the ""975 patent may be configured to spray texture materials, the device in the ""975 patent still has the problem of clogging or packing of the valve assembly by the particulates contained in the texture material for spraying, especially if the particulates are large, like those found in stucco or other heavy and particulate materials such as those mentioned above.
U.S. Pat. No. 5,037,011, issued to the present Applicant, discloses a spray apparatus for spraying a texture material through a nozzle. Similarly, in this apparatus, there exists a problem of spraying texture materials having large particulates, such as stucco, because the particulates clog up the valve opening within the spray apparatus.
Therefore, a long-standing need has existed to provide an apparatus that may be used to readily apply viscous, heavy and particulate materials in aerosol form, such as exterior stucco, heavy sand finishes, drywall and acoustic ceiling patching materials, fire suppressant materials, adhesive and bonding materials, and culinary sauces. Furthermore, the heavy and particulate materials to be applied should be contained in a hand-held applicator so that the materials may be conveniently stored, as well as dispensed, in a simple and convenient manner without clogging or packing the valve assembly of the applicator.
An object of the present invention is to provide a valve assembly for use in an aerosol spray can capable of spraying viscous materials or materials with large particulates without clogging or packing like traditional aerosol spray cans designed for spraying texture materials.
Another object of the present invention is to provide an inexpensive and economical means for matching surface texture of a repaired or patched surface area on a drywall panel, acoustic ceiling, or stucco-covered surface.
Another object of the present invention is to improve the appearance of patched or repaired areas on a textured surface by employing a spray-on hardenable texture material that covers the repaired or patched area and visually assumes the surface texture of the surrounding patched or repaired surface.
Another object of the present invention is to provide a hand-held dispensing unit containing a pressurized texture surface material for spray-on and direct application of the material in a liquid or semi-liquid form onto a repaired or patched area so that the surrounding patched or repaired surface will be visually and mechanically matched.
Another object of the present invention is to provide a valve assembly for use in an aerosol spray can capable of spraying highly-viscous materials, such as fire suppressant materials, adhesive and bonding materials, and culinary sauces, without clogging or packing like traditional aerosol spray cans when spraying these materials.
One embodiment of the valve assembly comprises a dip tube primarily disposed inside a container. A rod is disposed inside the dip tube so that it may move lengthwise within the dip tube. A sealing member is coupled to the bottom end of the rod, so as to form a tight-seal with the bottom opening of the dip tube when the rod is in an up position, and it exposes the bottom opening of the dip tube to the heavy and particulate material inside the container when the rod is in a down position. A bushing is also coupled to the top opening of the dip tube. Finally, an actuator is coupled to the top end of the rod and the bushing, allowing the user to depress on the actuator, thus lowering the rod to its down position and exposing the bottom opening of the dip tube to the material within the container, and allowing the heavy and/or particulate material to move up the dip tube and out of the container.
Another embodiment of the valve assembly comprises a dip tube primarily disposed inside the container. An interior tube is disposed inside the dip tube so that it may move lengthwise within the dip tube. There is at least one orifice at the bottom end of the interior tube. A top O-ring is coupled to the interior tube adjacent the at least one orifice to prevent any bypass of the heavy and particulate material into the dip tube, and a bottom O-ring is coupled to the bottom end of the interior tube to seal off the valve assembly when not actuated. The top opening of the dip tube may be coupled to a bushing. Finally, an actuator is coupled to the top end of the interior tube, allowing the user to depress on the actuator, thus lowering the interior tube to its down position and exposing the at least one orifice on the interior tube to the material inside the container and allowing the heavy and particulate material to flow up the interior tube and out of the container.
Yet another embodiment of the valve assembly comprises a dip tube primarily disposed inside the container. This dip tube may move lengthwise, and may extend beyond the top of the container. At least a portion of the dip tube rests within a sleeve located inside the container. A spring may engage both the sleeve and the dip tube, thereby having the dual effect of pushing the sleeve against the bottom of the container and the top of the dip tube out of the container. There is at least one orifice on the dip tube that is brought into alignment with an orifice on the sleeve when the dip tube is lowered incident to actuation. There is also at least a first seal coupled to the sleeve adjacent to and below the at least one orifice on the dip tube to form a seal to prevent bypass of the sprayable material into the dip tube when the dip tube is not actuated. There may also be a bushing coupled to the dip tube and adjacent to the top opening. Finally, an actuator is coupled to the top end of the dip tube. This allows the user to depress on the actuator, thus lowering the dip tube to its down position and aligning the at least one orifice on the dip tube with the at least one orifice on the sleeve, thereby allowing the sprayable heavy and particulate material to flow up the dip tube and out of the container.
A further embodiment of the valve assembly comprises a dip tube having a predetermined length that is primarily disposed within the container. This dip tube may move lengthwise, and may extend beyond the top of the container. There is also a valve core that is at least partially disposed within the dip tube, with a spring engaging both the valve core and the dip tube. This spring may be a rubber cylinder or a metal spring. The spring pushes the dip tube up and partially out of the container, while pushing the valve core against the bottom of the container. There is at least one orifice on the valve core and at least one orifice on the dip tube that are brought into alignment when the dip tube is lowered. There is also at least one seal located adjacent to and below the orifice on the valve core that prevents sprayable material from entering the dip tube when it is an up position. There may also be a bushing coupled to the dip tube and adjacent to the top opening in the container. This bushing may be a diaphragm that is coupled to the top of the container and the dip tube. Finally, an actuator is coupled to the top end of the dip tube. This allows the user to depress on the actuator, thus lowering the dip tube to its down position and aligning the at least one orifice on the dip tube with the at least one orifice on the valve core, thereby allowing the sprayable heavy and particulate material to flow up the dip tube and out of the container.
The above embodiments, and others, may be designed to spray a binary compound. The binary compound can be packaged within one aerosol system, yet kept in two separate portions until combined by the user. Such a configuration is particularly beneficial in the case of a system in which a catalyst is used. In one configuration, the catalyst is stored in the cavity created within a tube that extends into the aerosol system. For example, the catalyst may be stored within the cavity created within the dip tube of one of the above embodiments of the present invention when the interior tube or rod is in an up position. The catalyst may be released to mix with the sprayable material by lowering the rod or interior tube, thereby opening either the bottom of the dip tube or an orifice. The mixing of the two substances may be achieved by providing a storage cap as well as a spray tip. The user may depress the storage cap to lower the rod or interior tube and shake the aerosol system to mix the catalyst with the rest of the sprayable material. Once the two substances have mixed, the user then may replace the storage cap with the spray tip and spray as desired.
Alternatively, the catalyst may be stored in a receptacle that is connected to the dip tube inside the container at an orifice on the dip tube. In this configuration, when the interior tube is lowered incident to spraying, the orifice on the receptacle comes into alignment with an orifice on the dip tube. The flow of the catalyst may be controlled by altering the size of the orifice so that an appropriate amount of catalyst is mixed an appropriate amount of sprayable material. This configuration permits the user to control the timing of the mixing of the catalyst with the sprayable material so that the aerosol system may be utilized over a longer period of time.
When a heavy or particulate material is dispensed from an aerosol can, the material frequently clogs the spray nozzle or other parts of the apparatus. One reason that this may occur is that, in such materials, the velocity of the fluid and particles is not static. If the diameter or area of the space through which the material is flowing is increased, the velocity of the fluid declines. At the same time, the heavier or denser portions of the material slow down and tend to sink. This results in a partial separation of the material. Conversely, if the diameter or area of the space through which the material flows is decreased, the velocity of the fluid increases. Since it takes additional time for the heavier or denser portions of the material to gain velocity, these portions may aggregate and block the flow of the material. Once the heavier or denser portion starts to aggregate, it can filter heavy or dense portions from the material. This can continue until the backlog of this portion stops the flow of the more liquid portion of the spray.
The present invention prevents clogging or packing of the valve assembly because the valve opening is at the bottom of the container, as opposed to being at the top, as in traditional aerosol spray cans. The placement of the value opening at the bottom of the container greatly reduces the clogging or packing of the valve by texture materials having large particulates, since the reduction in cross section occurs much earlier in the spraying system. Further, the diameter of the valve opening may be varied in diameter, depending on the material being sprayed. This improvement allows the efficient and low-cost spraying of heavy and more highly-textured materials, because there is no longer the problem of clogging or packing of the valve opening by the particulates suspended within the texture material. Additionally, the diameter and length of the dip tube may be varied to allow for cosmetic variation in the pattern of the material sprayed.
Other features and advantages of the invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings that illustrate, by way of example, various features and embodiments of the invention.